Tyre size meaning

What does tyre size mean? There are two organizations, Tire and Rim Association (TRA), and European Tyre and Rim Technical Organisation (ETRTO), that influence tire standards. Essentially this is the height of the tyre as a percentage of the width. So, in the example, the tyre has an aspect ratio of 5 meaning the profile height is of its total width (10mm).

This is the measurement, in millimetres , from the tyre’s inner sidewall to its outer sidewall.

Is the diameter of the road wheel , expressed in inches. So, in the above example, a tyre that has an aspect ratio of would have a height equal to per cent of its width. This number represents a percentage of the tread width. For example, the height of this tyre is of its width. Low profile tyres have smaller aspect ratio percentages.

One way to define it, popular in times past, was to measure the tyre’s outside diameter and its maximum width when inflated , but this can be misleading. Your tyre size can be found on the sidewall of your current tyre and is a sequence of numbers and letters. By that, we mean the height of the sidewall expressed as a percentage of the width.

So this one would be 97. Almost all new car tyres are radials. In this case, it’s a 16” wheel. The profile of the tyre. Let’s take the tyre above as an example.

How to read the tyre sizes. This refers to the tyre being a radial type- this is like the majority of the tyres used today. Therefore, this radial tyre has a width of 205mm. With a standard tyre , the sidewall height is usually of the nominal section width. Can I use a different tyre size ? R means it is radial construction.

This dimension is clear and allows for precise classification of the rim size. Inch Marking (e.g. x 0) states the approximate outer diameter (inches) and the tire width (inches). This second number is that percent. Our Tyre Size Guide will clear up any confusion you have when selecting the right replacement tyre for your bike.

If you are looking for information about tyre choice for different disciplines, surfaces and performance goals, look at our Road Bike Tyre Guide or Mountain Bike Tyre Guide best tyre for your bike, including rubber compoun tread pattern, tyre pressure, puncture protection and weight.

A tyre speed rating indicates the maximum speed a tyre is legally approved for. When choosing the wheel size , you should also remember to take into account the width of the car tyre at the point of contact with the wheel. We recommend that you use the traditional sizing method wherever possible as most tyres that we stock use this system.

If there is no percentage indication in the tyre size , the tyre sidewall height is taken to be of the width. You may sometimes see a tyre with the in the size eg. Fortunately, Tyre Leader is here to help you. Wheel markings consist of a series of numbers and letters.

ET:wheel offset. By looking at it, at first instance, the cryptogram appears no less than a riddle. This is probably more to do with a rare size than the tyre being a run-flat.

In fact, run-flats should be simple to get hold of as there are only a handful of sizes , and it is easier for makers to. Tires with diameters 6mm and 6mm are both classified as 28-inch. Oddly enough, tires with an inner diameter of 6mm are classified as 27-inch.

These classifications originate from the time of tire brakes.